ads.txt for Publishers

Mobile publishers identify themselves to DSPs as authorized sellers by including an ads.txt file on their inventory.

Oath supports the industry-wide ads.txt initiative. We are partnering with both DSP's and supply sources to facilitate the enforcement of ads.txt files by our DSP partners.

What is ads.txt?

Ads.txt was created by the IAB to allow publishers to publicly declare the specific exchanges they work within the digital advertising space. The goal of ads.txt is to improve transparency and decrease fraud revenue.

How is the ads.txt file formatted?

The format for ads.txt file is: #< SSP/Exchange Domain >, < SellerAccountID >, < PaymentsType >, < TAGID >

This is an Oath example.

#ads.txt file sample
 , 12000, DIRECT #banner, US, 3679, DIRECT #video, US, 20459933223, DIRECT # banner, US, 25980889636, DIRECT # banner, CA, 4577, DIRECT #banner, app

How do I include Oath in my file?

To include Oath in your file, publishers must have at least 3 of the 4 mandatory fields inserted into the .txt file that you host. Each field is separated by a comma and each company has its own line of code.

Field #1 - The domain you enter here depends on the platform being monetized.

Platform Domain
Oath Ad Platforms SSP
Oath Ad Platforms Video SSP
ONE by AOL: Display
DSP, Gemini

Field #2 - Enter your Publisher ID (the ID we assigned and you pass in the ad call). If you don’t know your ID or need help finding it, reach out to an Account Manager.

Field #3 - Enter the type of relationship.

  • Direct
  • Reseller

Field #4 - Optional, if you choose to use it Oath's TAG ID is e1a5b5b6e3255540.

What happens next?

DSP’s actively crawl the web looking for ads.txt files and the data they contain. Oath’s code appearing in the file confirms that the inventory is held by an authorized seller.

*Please note the ads.txt file information applies to all Oath platforms, not just the SSP.


Ads.txt FAQ’s

Q: What does ADS stand for?

A: Authorized Digital Sellers

Q: Which platforms could be impacted?

A: Ads.txt works on all of Oath platforms, SSP (mobile web inventory only, not in-app), Video SSP and DSP. Ads.txt is working to eliminate counterfeit or spoofed inventory and prevent the reselling of an unauthorized impression. This can impact all resellers on the above-listed supply platforms.

Q: Does a non-authorized seller mean they have invalid traffic?

A: No, not necessarily. It may mean the inventory is being resold without the publisher's knowledge, the partner didn't get added to the ads.txt file in time for publication or was inadvertently left out. It could also mean the publishers decided to not participate.

Q: Can I see a current example of a live ads.txt file?

A: View examples of live ads.txt files at or

Q: What is the Certification Authority ID? And does Oath have one?

A: A Certification Authority ID uniquely identifies the advertising system (this ID maps to the entity listed in Field #1). The Certification Authority ID is optional and appears in Field #4.

Oath is certified for malware (as of September 2018) by the Trustworthy Accountability Group (aka TAG). Our TAG ID is e1a5b5b6e3255540. Use our TAG ID on your ads.txt file for our entries.

More info and examples can be found in the IAB OpenRTB ads.txt Spec on pages 6 & 8.

Q: Are ID’s consistent across Oath’s platform?

A: No, ID’s can vary from product to product as well as country to country. The Exchange/Seat ID would be the Publisher's Network ID in Oath Ad Platforms. If a Publisher is set up in both US and EU, they must enter two lines in their ads.txt file - one for each Network ID.

Q: I work with you through a Header Tag (via Prebid), can I use the Publisher ID that corresponds to that integration?

A: Yes, the PubID is the same.

Q: Does the Oath exchange offer my inventory on other exchanges on my behalf?

A: Yes, we work with exchanges who are resellers. It is up to the publisher to authorize these resellers in their ads.txt file. We recommend working with your account manager to make sure  the correct reseller information is included.

Q: Can I see a sample crawler for demand partners?

A: Yes, please reference the IAB page here.

Q: Do all SSP’s use publisher ID?

A: Most SSP’s use publisher ID; but that depends on the partner’s platform. We recommend you reach out directly to individual SSP’s.

Q: What are the code lines starting with the # symbol?

A: These are considered comments and are ignored by the system.

Q: Do you have an SSP sample bid request for mobile devices?

A: Yes, see the sample bid request below for mobile.

"publisher": {
       "id" : "17382",
       "Name" : "PRO12 Mobile",
       "Ext" : {
       "Nex_else" : 0

Q. Do you have an SSP sample bid request for display?

A: Yes, see the sample bid request below for display.

"site": {
     "id": "50-1234",
     "page": "",
     "publisher": {
     "id": "50"

Q: Is Oath actively crawling the web for ads.txt files?

A: Yes, we started crawling in September 2017.

Q: What happens if no ads.txt file is present?

A: DSPs can interpret the absence of ads.txt files in two ways:

  • Assume that no advertising is unauthorized because no file is present
  • Reach out to the publisher to get authorization to sell inventory

Q: What if DSPs want to target/exclude based on one or more of these options?

  • Authorized reseller
  • Non-Participating
  • Non-authorized reseller

A: Targeting (including or excluding seller’s inventory) is controlled by the DSP. Once ads.txt becomes widely adopted, we anticipate DSP’s will make bid decisions based on information they find in specific ads.txt files.

Still have questions? Please reach out to your account manager.

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